Using electricity instead of high-pressure or heat to remove salt from seawater, the team produced a metric cube of pure drinking water - with 1.5 kWh.

Advanced desalination methods around the world currently use twice that amount of energy.

Recycled water, also known here as Newater, requires 0.7kWh to produce.

By passing seawater through electric fields, salt is drawn out - the complete opposite of conventional methods which push water through a membrane, explained Siemens vice-president of R&D Ruediger Knauf.